1. The Field of the Invention
This invention generally relates to exercise equipment and, more specifically, to elliptical exercise machines.
2. The Relevant Technology
Exercise machines having alternating reciprocating foot supports configured to traverse or travel about a closed path to simulate a striding, running, walking, and/or a climbing motion for the individual using the machine are well known in the art, and are commonly referred to as elliptical exercise machines or elliptical cross-trainers. In general, an elliptical or elliptical-type exercise machine comprises a pair of reciprocating foot supports designed to receive and support the feet of a user. Each reciprocating foot support has at least one end supported for rotational motion about a pivot point, with the other end supported in a manner configured to cause the reciprocating foot support to travel or traverse a closed path, such as a reciprocating elliptical or oblong path or other similar geometric outline. Therefore, upon operation of the exercise machine, each reciprocating foot support is caused to travel or traverse the closed path, thereby simulating a striding motion of the user for exercise purposes. The reciprocating foot supports are configured to be out of phase with one another by 180 degrees in order to simulate a proper and natural alternating stride motion.
An individual may utilize an elliptical exercise machine by placing his or her feet onto the reciprocating foot supports. The individual may then actuate the exercise machine for any desired length of time to cause the reciprocating foot supports to repeatedly travel their respective closed paths, which action effectively results in a series of strides achieved by the individual to obtain exercise, with a low-impact advantage. An elliptical exercise machine may further comprise mechanisms or systems for increasing the resistance of the motion. In addition, the reciprocating motion of the feet to achieve a series of strides may be complemented by a reciprocating movement of the arms, whether assisted by the exercise machine via a suitably configured mechanism or system, or unassisted.
Although elliptical exercise machines may comprise mechanisms or systems for increasing the resistance of motion, there is no practical way to readily adjust the level of exercise on a given machine. It is, therefore, an object of the present invention to provide a mechanism to readily vary the level of exercise on an elliptical exercise machine.